1. Field of Invention
This invention relates to a process for biologically preventing dicotyledonous plant diseases by cutting a seedling of a dicotyledon, immersing the cut seedlings into asymbiotical bacteria suspension, and cutting the seedlings in a nursery bed or directly planting them in a field.
2. Description of the Prior Art
Recently, vegetables are produced year-round, and they are repeatedly cultivated on the same land. The repeated cultivation of the same vegetables on the same land brings about injury by continuous cropping by soil disease which impedes continuous and safe production of the vegetables.
In order to overcome injury by continuous cropping, it has been proposed to disinfect the soil by chloropicrin or methylbromide, to grow a new type of vegetable having antifungal activity or to cut a seedling into a new type of stock having antifungal activity.
Disinfection of the soil, however, has the environmental drawbacks such that it is not only expensive, but is toxic to men and beasts.
Improvement of a plant having antifungal activity is problematic in that it takes much labor and almost 10 years to grow an improved new plant.
Graft cropping has other problems such that the cost of a seedling and labor of cultivating the new seedling increase unexpectedly so that a new technical method has been needed in the production field.
On the other and, some processes for biologically preventing dicotyledon diseases using antifungal activity have been widely employed.
Certainly, useful bacteria having some antifungal activity to other bacteria can be easily isolated from soil or plants.
When the useful bacteria are put into the soil or spread on the plant as they are, their antifungal activity cannot be exhibited at all because the useful bacteria do not survive in the soil or in the plant.
To this end, a method of stabilizing useful bacteria in the soil by adsorbing the useful bacteria into a carrier and a method of producing useful bacteria which are associated with a plant by improving bacteria have been tried. These method, however, have problems in that they ignore specificity of species, their functions are not exhibited sufficiently, and the growing environment and ecosystem are ignored. As a result, there is not enough of the aforementioned soil disinfection, or growth of a new type of plant having anti-fungal activity, or cutting the new plant into a stock having antifungal activity.